On Mon, 25 Jan 2021 04:21:18 +0100,
Hui Wang wrote:
>
> This change adds audio jack injection feature through debugfs, with
> this feature, we could validate alsa userspace changes by injecting
> plugin or plugout events to the non-phantom audio jacks.
>
> With this change, the sound core will build the folders
> $debugfs_mount_dir/sound/cardN if SND_DEBUG and DEBUG_FS are enabled.
> And if users also enable the SND_JACK_INJECTION_DEBUG, the jack
> injection nodes will be built in the folder cardN like below:
>
> $tree $debugfs_mount_dir/sound
> $debugfs_mount_dir/sound
> ├── card0
> │ ├── HDMI_DP_pcm_10_Jack
> │ │ ├── jackin_inject
> │ │ ├── kctl_id
> │ │ ├── mask_bits
> │ │ ├── status
> │ │ ├── sw_inject_enable
> │ │ └── type
> ...
> │ └── HDMI_DP_pcm_9_Jack
> │ ├── jackin_inject
> │ ├── kctl_id
> │ ├── mask_bits
> │ ├── status
> │ ├── sw_inject_enable
> │ └── type
> └── card1
> ├── HDMI_DP_pcm_5_Jack
> │ ├── jackin_inject
> │ ├── kctl_id
> │ ├── mask_bits
> │ ├── status
> │ ├── sw_inject_enable
> │ └── type
> ...
> ├── Headphone_Jack
> │ ├── jackin_inject
> │ ├── kctl_id
> │ ├── mask_bits
> │ ├── status
> │ ├── sw_inject_enable
> │ └── type
> └── Headset_Mic_Jack
> ├── jackin_inject
> ├── kctl_id
> ├── mask_bits
> ├── status
> ├── sw_inject_enable
> └── type
>
> The nodes kctl_id, mask_bits, status and type are read-only, users
> could check jack or jack_kctl's information through them.
>
> The nodes sw_inject_enable and jackin_inject are directly used for
> injection. The sw_inject_enable is read-write, users could check if
> software injection is enabled or not on this jack, and users could
> echo 1 or 0 to enable or disable software injection on this jack. Once
> the injection is enabled, the jack will not change by hardware events
> anymore, once the injection is disabled, the jack will restore the
> last reported hardware events to the jack. The jackin_inject is
> write-only, if the injection is enabled, users could echo 1 or 0 to
> this node to inject plugin or plugout events to this jack.
>
> For the detailed usage information on these nodes, please refer to
> Documentation/sound/designs/jack-injection.rst.
>
> Reviewed-by: Takashi Iwai <tiwai@xxxxxxx>
> Reviewed-by: Jaroslav Kysela <perex@xxxxxxxx>
> Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
> Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx>
Some minor nitpicking:
> +static int snd_jack_debugfs_add_inject_node(struct snd_jack *jack,
> + struct snd_jack_kctl *jack_kctl)
> +{
> + char *tname;
> + int i;
> +
> + tname = kstrdup(jack_kctl->kctl->id.name, GFP_KERNEL);
> + if (!tname)
> + return -ENOMEM;
> +
> + /* replace the chars which are not suitable for folder's name with _ */
> + for (i = 0; i < strlen(tname); i++)
No need to use strlen(), just check the NUL character on tname[i].
> --- a/sound/core/sound.c
> +++ b/sound/core/sound.c
> @@ -9,6 +9,7 @@
> #include <linux/time.h>
> #include <linux/device.h>
> #include <linux/module.h>
> +#include <linux/debugfs.h>
> #include <sound/core.h>
> #include <sound/minors.h>
> #include <sound/info.h>
> @@ -39,6 +40,9 @@ MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
> int snd_ecards_limit;
> EXPORT_SYMBOL(snd_ecards_limit);
>
> +struct dentry *sound_debugfs_root;
> +EXPORT_SYMBOL_GPL(sound_debugfs_root);
I guess this should be wrapped with CONFIG_SND_DEBUG ifdef?
thanks,
Takashi
